You might have tonsil stones!
And if you are drinking gingerale or 7up for nause, that makes it worse.
I know exactly what your talking about. My doctor told me its from excessive stomach acid and prescribed me a nausea medicine. Its a little pink strawberry flavored pill that dissolves in your mouth. That taste that your having, im still dealing with and im 17 weeks now. Its just not as intense as before.
Does it taste like metal at all? If so, it's a common complaint while pregnant. The best fix for it is food, if you're able to stomach it.